Dental crown structure



J. E. ROSE.

DENTAL CROWN STRUCTURE.

APPLICATION FILED MAR -13,1918- Patented Aug. 8, 1922.

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JOSEPH JELON ROSE, 0F PURTLAND, OREGUN.

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Specification of Letters Patent.

Patented Aug. 8, 19922.

Application filed March 13, 191%. Serial Ito. 222,052.

Another object of the invention is to provide a crown structure in whichthe crown coIn-' prises a jacket having the exterior configuration andcolor of a natural tooth.

lln carrying out the invention the enveloping jacket is preferablycomposed of porcelain and a base of gold is interposed between it andthe prepared natural tooth, the parts being held together by a suitableadhesive, such as dental cement. The base may be in the form of a ringwhich engages the upper portion of the interior wall of the jacket, orin the form of a shell which engages practically all portions of theinterior wall of the jacket. The latter, of course, provides the morerigid structure and is preferable for bridge work.

The invention will be more fully understood upon reference to thefollowing description taken in connection with the ac-- companyingdrawings, and the scope of the invention will be particularly pointedout in the appended claims.

Referring to the drawing, Fig. 1 is a front elevation of a dental bridgestructure, having abutments constructed according to the presentinvention; Fig. 2 is a rear elevation of the same; Fig. 3 is aperspective view of a portion of said bridge structure, showing theabutment crown in central vertical section; Fig. 4 is a view of anindividual crown shown in vertical section in position on a preparedtooth, said-view illustrating the gold base in the form of a shell, andFig. 5 is a similar view illustrating the gold base in the form of aband or ring. Throughout these views like reference characters refer tolike parts.

Referring to said drawing in detail, A and B designate the abutmentcrowns of the bridge structure C. The latter structure includes a bridge10 of gold and a plurality of teeth 11 suitably secured'thereto. At eachend, the bridge 10 is formed integral with or suitably secured to thebase of gold forming part of the abutment crown. Since the crowns A andB are alike, it will suflice to describe the structure of crown A only.This structure includes the acket 12 of porcelain or like. material andthe base 13 of gold.

which is preferably in the form of a shell which fits against allportions of the inner wall of the jacket 12. The jacket is given anexterior shape which conforms to that of the natural tooth which it isintended to replace. It is also composed of a material, preferablyporcelain, which has a color closely approaching that of a naturaltooth. The gold base 13 preferably extends slightly beyond the open endof the jacket 12 and its exposed exterior portion is made flush with theadjacent portion of the acket so that its exterior surface forms anextension of the exterior surface of the jacket 12. This exposed portionof the base 13 preferably forms a band or ring which finishes off theopen end of the jacket. The base 13 may be secured to the jacket 12 byan interposed adhesive, such as dental. cement.

In practice many jackets can be made up and kept on hand. These willvary in size and shape according to the difierent shapes and sizes ofnatural teeth.

When it is desired to make a crown, the naturaltooth, such as the toothdesignated 14, is prepared by removing the enamel, then a suitablyselected jacket 12 isfitted over the prepared tooth, with two sheets ofgold foil, separated by a layer of wax, intervening. The foil and waxwhen fitted and trimmed will take the shape of the finished base 13.Then the jacket together with the foil and wax are carefully removedfrom the tooth 14, and finally the foil and wax is removed from thejacket 12, care being taken not to change its shape. The wax and foilform is then invested in a suitable material such as plaster of Paris,with a small portion of the wax exposed. The wax is then burned out andthe gold is flowed in to take its place. When removed from the investingmaterial and properly finished this constitutes gold base 13, which isto be fitted into jacket 12 and cemented into place by the use of dentalcement or other adhesive. With the final polish the crown is,

now ready for application to the prepared tooth. This is done by merelyapplying an adhesive to the interior of the base and fitting the wholeupon the tooth 14, where it will be held by an adhesive. Of course, inthe case of the. bridge construction, both abutment crowns should be setat the same time.

In case the base is a ring instead of a shell, it is formed in the sameway but the a foil and the wax are cutaway before investing so astoleave a gold base like 1-3 of- Figure 5. In such case the gold, baseis not interposed between the endportion of the tooth 1 4: and thejacket 12 but the latter bears directly upon that portion of the toothwith the adhesive intervening.

It will be understood that the jackets can be produced by a manufacturerwhile the work upon the base is done by the dentist.

Other ways may be employed for preparing the base of gold and more orless of the base may be allowed to show when the crown having itsexterior surface secured to the 3 interior of said jacket and having itsinterior surface adapted to be secured to the exterior of the preparedtooth by an adhesive.

.2. A dental crown structure comprising an enveloping jacket having theexterior configuration and color of a natural tooth and open at one endso as to be readily slipped over a prepared tooth, and a base of goldfitted into the interior of said jacket at its open end and having anexterior surface forming an extension of the exterior surface of theadjacent portion of said jacket.

3. A dental crown structure comprising an enveloping jacket having theexterior configuration and color of a natural tooth and open atone endso as to be readily slipped over a prepared tooth, and a base of goldconstituting a shell fitted into the interior of said jacket and firmlysecuredend of said jacket, said portion having exterior faces flush withand extending the faces of the adjacent portions of said jacket. .4. Adental structure comprising abridge of gold, teeth secured thereto, anabutmentbase of gold to which said bridge is secured, saidbase beingshaped-to fit upon and be secured to a prepared tooth, and an enclosingjacket fitting upon and secured to a portion of said base and -havingthe exterior configuration and color of a natural tooth.

having a cavity of a size to receive the prepared crown of the naturaltooth and having at the open end of the cavity a surface encircling thecavity and approximately'perpendicular to the axis of thecavity andadapted to abut a shoulder formed between the natural tooth crown andthe root, and having within the cavity a matrix of metal having amarginal flange fitting the said end surface of the porcelain jacketcrown.

6. -A jacket crown having a cavity of a size to receive the preparedcrown of a-.nat-' ural tooth, and having the said cavity lined with amatrix of metal.

7. A tooth crown comprising a jacket crown having a cavity to receive a,natural crown and a lining matrix formed to fit said cavity.

In testimony whereof I have hereunto subscribed my name this 15th day ofFebruary,

A. D. 1918. 1 JOSEPH E-LON ROS-E.

thereto, said shell having a portion extending beyond the open 5. Ajacket crown for teeth of porcelain

